equinumerous
Adjective
Meaning
equinumerous (not comparable)
(mathematics) Having equal cardinality.
Examples
It is thus said that two sets with the same cardinality are, respectively, equipotent, equipollent, or equinumerous.
Previously, all infinite collections had been implicitly assumed to be equinumerous (that is, of "the same size" or having the same number of elements).